my team and i here shot over 6 case of madbull .20 and .25 never had jam or break.
Also i wonder how did a bb broke your piston since tapet plate is loose and holded with a spring its not really related.

Ment.

jams barrel, piston gets held half way back from the air pressure then the gear strips those teeth that are still moving forward.
It's not the bbs that strip the piston its the air pressure caused by the jam thats caused by the bbs.